To develop high power LED lighting system makes the highly efficient heat removal and dissipation critical for reliable operation of the LED lighting devices and systems. Hence the industry is in an urgent need of novel thermally conductive materials suitable for various thermal management applications on LED lighting. It is especially beneficial if such materials are electrically insulating since it would make it possible to apply them directly on the electronic circuitry. Unfortunately, most of the economically viable insulating materials are characterized by low thermal conductivity, which seriously limits their application as efficient heat spreaders.
It has been long known that bulk hexagonal boron nitride (hBN) possess one of the highest basal plane thermal conductivities among other materials (up to 400 W/m·K at room temperature) and almost matches that of silver. The more recent interest in hBN has been motivated by the search of an electrically insulating counterpart of graphene suitable for thermal management applications. Apart from excellent dielectric properties, few atomic layer hBN crystals demonstrated high values of thermal conductivity approaching its bulk value, and ultimately predicted to exceed those. Considering the rare combination of the electrical insulating behaviour with exceptionally high thermal conductivity hexagonal boron nitride is a promising candidate for the next-generation thermal management materials. However to exploit the remarkable properties of the few-layer hBN crystals for practical applications would require thermally conductive layers to be either flexible or conformal with the surface, and to have little heat junction within channel in a preferred orientation. All of those requirements can be satisfied by obtaining laminates consistent of thin (preferable monolayer) hBN crystals. It has been demonstrated before that graphene laminates possess relatively high thermal conductivity (up to 100 W/m·K) alongside with perfect coating properties. Unfortunately, the number of potential thermal management applications of such graphene laminates is limited by their high electrical conductivity. On the other hand, hBN laminates are also expected to provide high thermal conductivity in conjunction with excellent electrical insulating properties, which can potentially become a paradigm changer for the electronic industry.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.